class Email(object):
    """
    This class represents a Email.
    """

    def __init__(self, identifier, date, author_name, author_email,
                 subject, message, in_reply_to=None):
        """
        Constructor.
        """
        
        self.id = identifier
        self.date = date
        self.author_name = author_name
        self.author_email = author_email
        self.subject = subject
        self.message = message
        self.in_reply_to = in_reply_to
        
    def __eq__(self, other):
        return self.id == other.id
